1. Field of the Invention
This invention pertains to systems for applying electrical signals to an anatomical feature of a patient. While many of the disclosed concepts are applicable to a wide variety of therapies (e.g., cardiac pacing with electrodes applied to heart tissue), the invention is described in a preferred embodiment where the invention pertains to the treatment of disorders such as obesity, pancreatitis, irritable bowel syndrome, diabetes, hypertension, metabolic disease, and inflammatory disorders. In a most preferred embodiment, this invention pertains to the treatment of a gastrointestinal disorder by the application of a high frequency signal to a vagus nerve of a patient.
2. Background
A blocking therapy can be used alone or in combination with traditional electrical nerve stimulation in which impulses are created for propagation along a nerve. The disorders to be treated include, without limitation, functional gastrointestinal disorders (FGIDs) (such as functional dyspepsia (dysmotility-like) and irritable bowel syndrome (IBS)), gastroparesis, gastroesophageal reflux disease (GERD), obesity, pancreatitis, diabetes, hypertension, metabolic disease, inflammation, discomfort and other disorders.
In a blocking therapy, an electrode (or multiple electrodes) is placed on or near a vagus nerve or nerves of a patient. By “near”, it is meant close enough that a field created by the electrode captures the nerve. Higher frequencies (e.g., 2,500 Hz-20,000 Hz) are believed to result in more consistent neural conduction block. Particularly, the nerve conduction block is applied with an electrical signal selected to block the entire cross-section of the nerve (e.g., both afferent and efferent signals on both myelinated and non-myelinated fibers) at the site of application of the blocking signal.
A complete system for applying a signal to a nerve may include systems for addressing the potential for charge build-up, assuring good communication between implanted and external components, recharging implantable batteries, safety of the device, physician and patient controls and programming and communication with the system.